Internal Lock folder

[Mack (renamed)]

I'm looking for info on an internal lock folding knife. This knife has an internal locking catch that unlocks the blade for opening when the blade tip is pointed up and pressed in. When folding and the tip is pointed down and pressed in the catch holds the blade closed. It has a stainless steel handle that is perfect for engraving. I would like to buy several for gifts to friends. It is a small pocket knife and has no manufacturer name of the blade. It does have some numbers which I assume are patent numbers. Any info would be greatly appreciated.